Discrete-time adaptive sliding mode controller for vehicle steering systems with preview

This paper presents the design of a vehicle steering system with preview for a vehicle model subject to an uncertain side aerodynamic force by the crosswind disturbance. The steering control with preview is automatically implemented by steering the angles of the front/rear wheels based on the discrete-time adaptive sliding mode controller (SMC). It is assumed that the measurement of the states is taken by the measurement constraint and the contamination with independent random noises. The estimates for the unmeasurable states and the uncertainty characterizing the side aerodynamic force are respectively obtained by the weighted least squares estimator using a set of noisy measurements, and the proposed discrete-time adaptive SMC is designed on the basis of the information of the estimates. The simulation result indicates that the proposed vehicle steering system with preview is very effective in the system performance and the practical implementation.